Warning apparatus for an internal combustion engine



H. J. BOWER Dec. 23, 1969 WARNING APPARATUS FOR AN INTERNAL COMBUSTIONENGINE- 2 Sheets-Sheet 1 Filed July 29 1968 INVENTOR. HARMON I. BowE-RBYMMJJ$$MM ATTORNEY 5 Dec. 23, 1969 H. J. BOWER WARNING APPARATUS FOR ANINTERNAL COMBUSTION ENGINE Filed July 29 2 Sheets-Sheet 2 INVENTOR.HARMAN J. BowE- alive, I

ATTORNEYS United States atent O 3 485,203 WARNING AFIARAiTUS FOR ANINTERNAL CUMBUSTIQN ENGINE Harman J. Bower, P19. Box 574, Winston-Salem,N11. 27102 Filed July 29, I968, Ser. No. 743,312 Int. Ci. G011 19/12 US.Cl. 11670 ABSTRACT (IF THE DISCLOSURE WNW t...

In many applications where power from a prime mover is required, thepower source of choice is an internal combustion engine. While suchengines have significant advantages for such applications, the enginesadditionally suffer from certain disadvantages. The primary disadvantageis that the engines are subject to incapacitating damage shouldoperation of an engine be attempted or be permitted to continue whilethe engine is in an improper condition.

While the number of possible improper conditions of an engine isrelatively great, many of the conditions are self-incapacitating, andwill interrupt operation of the engine or preclude starting operation ofthe engine. Two particular conditions are, however, notself-incapacitating until major damage has been done to the engine.These conditions result from failure of certain accessory systemsincluded in order to assure operation of the engine. More specifically,most internal combustion engines employed as prime movers are liquidcooled, and include an engine driven pump operative to circulate aliquid through heat exchange passages in the engine and to a heatexchange device, such as a radiator. Regardless of whether or not anengine relies upon a liquid coolant system of this type, the circulationof oil to the lubricated parts of the engine is invariably required inorder to assure proper lubrication. Such lubricant systems typicallyinclude an engine driven pump circulating lubricant from a reservoirsuch as a sump in the crankcase of the engine to the various engineparts.

As to both of these liquid circulating systems, it is possible that animproper operating condition may occur without immediate damage to theengine. However, continued operation of the engine will result incritical damage thereto. Thus, it would be preferable that an operatorof the engine be warned against any improper operating conditionaffecting the coolant and lubricant circuits.

With the above discussion in mind, it is an object of my invention toprovide apparatus which, in combination with an internal combustionengine having a pump circulating liquid therethrough during operation ofthe engine, will function to warn an operator of the engine of animproper operating condition. In realizing this object of the invention,I provide apparatus which may be adapted for response either to animproper operating condition in a coolant flow circuit or to an improperoperating condition in a lubricant flow circuit. In particular, theapparatus in accordance with my invention includes a visual signal meanshaving an annunciator member movable between extended and retractedpositions and operatively connected with a liquid flow circuit of theinternal combustion engine in such a manner that fluctuations in pres-Patented Dec. 23, 1969 sure developed in the circuit during normaloperations cause the annunciator member to move between the extended andretracted positions on changes in the operation of the engine whichcause significant differences in pressure in the circuit. In view ofthis normal movement of the annunciator member, a failure of suchmovement or movement at an abnormal time effectively warns the operatorof the engine that the engine is operating improperly.

Some of the objects and advantages of the invention having been stated,others will appear as the description proceeds, when taken in connectionwith the accompanying drawings, in which- FIGURE 1 is a schematicillustration of the combination of my invention as arranged to warn anoperator of an improper lubricant circuit operating condition;

FIGURE 2 is an elevation view, in section, through a valve meansincluded in the combination of FIGURE 1;

FIGURE 3 is an end elevation view, in section, through a portion of thevalve structure of FIGURE 2, taken generally along the line 33 in thatfigure;

FIGURE 4 is an elevation view, in section, through a visual signal meansused in the combination of FIG- URE 1;

FIGURE 5 is a view similar to FIGURE 1 showing the application of myinvention to the coolant flow circuit of an internal combustion engine;

FIGURE 6 is a view similar to FIGURE 4 of the visual signal meansincluded in the combination of FIG- URE 5; and

FIGURE 7 is an elevation view in section through a portion of the visualsignal means of FIGURE 6, taken generally along the line 7-7 in thatfigure.

Referring now more particularly to the drawings, the combination of myinvention is there illustrated as arranged for warning an operator of animproper operating condition in the lubricant fiow circuit of aninternal combustion engine (FIGURES 1-4) and as arranged for warning anoperator of an improper operating condition in the coolant flow circuitof an internal combustion engine (FIGURES 57). The present discussionwill proceed first with reference to the combination as arranged forwarning an operator of an improper lubricant flow circuit operatingcondition.

In the combination illustrated in FIGURE 1, it is as sumed for purposesof illustration only that the internal combustion engine It) is employedto provide motive power for a self-propelled vehicle, such as a bus or atruck. While this is a common use of internal combustion engine primemovers and provides an environment for disclosure of the combination ofmy invention, it is to be understood at the outset that the usefulnessof my invention has a wider scope than application only to automotivevehicles. Included in the engine 10 is a lubricant circulating pump 11,typically driven by operative connection with the main shaft of theengine 10, in a conventional manner. The lubricant pump 11 withdraws oilor other suitable lubricant from a reservoir 12 such as the pan portionof the crankcase for the engine 10, and circulates the lubricant to thebearings and other lubricated parts of the engine as is conventionallyknown.

In order to advise an operator of the engine 10 of an improper lubricantflow circuit condition, the combination of my invention includes ahousing generally indicated at 20 and visual signal means supported bythe housing in position for ready observation by an operator of theengine It). In the particular environment illustrated in FIGURE 1, thehousing 20 may be mounted in position above the windshield through whichthe operator of the engine 19 views the road or path of travel of theautomotive vehicle driven by the engine 10. The visual signal meansincludes an annunciator member preferably in the form of a pivoting flag21 engaged by an actuating rod 22 and mounted on the housing 2% formovement between extended and retracted positions (as respectively shownby the full line and phantom line positions of FIGURE 4).

In order to assure movement of the pivoting flag 21 in the desiredmanner, the flag is mounted on the housing for movement relative theretoabout a pivot axis determined by a pivot pin 24, and the actuating rod22 penetrates the housing 20 and is positioned to transmit movement tothe pivoting flag 21 at a cam surface 25 by movement of the actuatingrod 22 along a line spaced from the pivot axis defined by the pin 24.Preferably, an antifriction member such as a bearing ball 26 isinterposed between an end of the actuating rod 22 and the cam surface 25of the pivoting flag 21, in order to assure low friction engagement ofthe respective surfaces upon transmission of movement. As the actuatingrod 22 is moved to an extended position, under the influence of forcesto be discussed more fully hereinafter, the pivoting flag 21 is movedfrom the extended position (solid lines in FIGURE 4) to the retractedposition (phantom lines in FIGURE 4).

In order to transmit to the annunciator member of the visual signalmeans movement which is indicative of the operating condition of theengine 10, the apparatus of my invention includes a displaceable membermounted within the housing 20 for defining therewith an expansiblechamber. Preferably, the displaceable member is a flexible diaphragmmembrane 28, clamped in place between an upper housing member 29 and alower housing member 30 which receives and supports the actuating rod 22and pivoting flag 21. The diaphragm membrane 28 may be made of anysuitable material adaptable to diaphragm construction, such as a plasticfilm, a rubberized fabric, or similar known materials. By being clampedin place between the upper and lower housing members 29 and 36, thediaphragm membrane 28 provides a flexible wall for an expansible chamber31 therewithin. The diaphragm membrane 28 is operatively connected tothe visual signal means, preferably by having the actuating rod 22 'penetrate the central portion of the membrane 28 and be secured withappropriate reinforcing washers on the opposite faces thereof. By thisoperative connection, movement of the membrane 28 within the housing 20with expansion and contraction of the volume of the chamber 31 istransmitted to the visual signal means.

In order to normally bias the visual signal means toward one of theselected positions, means are provided for resiliently biasing thediaphragm membrane 28 toward a reduced chamber volume position.Preferably, the resilient biasing means is a compression spring 32,positioned encircling the actuating rod 22 for engagement with the lowerhousing member 30. Upon movement of the diaphragm membrane 28 toward aposition at which the volume of the chamber 31 is'enlarged, the spring32 is compressed and provides a resilient biasing force tending toreturn the actuating rod 22 to the retracted position and the pivotingflag 21 to the extended position.

In order to permit movement of the pivoting flag 21 in response tofluctuations in pressure developed by the lubricant pump 11 duringnormal engine operation, the combination of my invention furtherincludes means for normally establishing operative communication betweenthe expansible chamber 31 within the housing 20 and the lubricant pump11, for normally transmitting to the diaphragm member 28 the pressuredeveloped by the pump 11 in circulating liquid through the engine. Inthe combination with which the present discussion is concerned, themeans for normally establishing operative communication betweenexpansible chamber 31 and the pump 11 includes a conduit 34 (FIGURES 1and 4) communicating with the expansible chamber 31, a conduit 35communicating with the discharge side of the lubricant pump 11, and avalve means 35 (FIGURES l, 2 and 3) interposed between the conduits 34and 35 for controlling the transmission of pressure therethrough. Thevalve means 36 is provided in order that the apparatus be responsive toan undesirable lowering of the quantity of lubricant held in thereservoir 12, and includes a float member 38 disposed within thereservoir 12 and movable in response to fluctuations in the level oflubricant therein. Normally, the float 38 is immersed wholly in andbuoyed upwardly by the quantity of lubricant retained in the reservoir12 (in the dotted line position of FIGURE 2).

The float member 38 is mounted on and pivotally movable relative to avalve body 39, with which the conduits 34 and 35 communicate. Operativecommunication between the conduits 34 and 35 is controlled by a valvemember disposed within the valve body 39 and movable relative to a valveseat provided in a valve passage which joins the conduits 34 and 35. Thevalve body 40 moves in response to movement of the float member 38.between a passage open position removed from the valve seat when thequantity of lubricant retained in the reservoir 12 is suflicient to buoythe float member 38 to the phantom line position in FIGURE 2 and apassage closed position in which the valve member 40 is seated when thequantity of lubricant in the reservoir 12 drops to such a level that theweight of the float member 38 acts on the valve member 40.

In order to release the pivoting flag 21 for movement to the extendedposition upon seating of the valve member 49, and to thus warn theoperator of the engine 10 that the lubricant level has dropped to acritically low point, the valve member 4% has a spool configuration andcooperates in a particular manner with the passages through the valvebody 39 (FIGURES 2 and 3). As illustrated, the valve member 40 has aconical seat engaging nose, a main body portion having a diameter lessthan that of the passageway within which the member moves, and a guidingflange portion adjacent the lower end of the member which sealinglyengages the passageway. The length of the valve member 4% and thedistance over which it moves in response to movement by the float 38 arecor related in such a manner that the flange portion of the ember 40blocks communication between the conduit 35 connecting the valve 36 tothe signal housing 20 during normal engine operation, so that lubricantpump pressure is passed thereto. Upon the level of lubricant falling toan undesirably low condition, the value member 40 seats to blockcommunication between the conduits 34 and 35, while movement of theflange portion thereof open direct communication between the conduit 35and the lubricant sump 12 thereby permitting the release of pressurefrom the housing 20.

The various elements of the combination of my invention now having beendescribed, with reference to a system for indicating an improperlubricant flow circuit operating condition, the operation of theapparatus will now be more fully pointed out. With a normal quantity oflubricant retained in the reservoir 12, the valve body 40 is withdrawnfrom the valve seat and free communication is established between theexpansible chamber 31 within the housing 20- and the discharge side ofthe lubricant pump ill. With the engine in a non-operating condition, nopressure is present in the conduits 34 and 35 or in the expansiblechamber 31 and the pivoting flag 21 is thus moved to the extendedposition by the retraction of the actuating rod 22 under the influenceof the spring 32-. Then, upon starting of the engine, the pressureproduced by the lubricant pump 11 is applied through the conduits 34 and35 and the valve means 36 to the expansible chamber 31 and the membrane28. Overcoming the biasing force of the spring 32, the pressure of thelubricant pushes the diaphragm membrane 28 to the expanded chamberposition, extends the actuating rod 22, and moves the pivoting flag 21to the retracted positioncThus, an operator of the engine should observethat the visual signal means is in the extended position prior tostart-up of the engine, and moves to the retracted position promptly asthe engine starts.

With continued operation of the engine, the annunciator member isretained in the retracted position. Should the quantity of lubricantretained in the reservoir 12 be maintained at the proper levelthroughout the period of operation of the engine and until the engine isstopped, the reduction of pressure in the conduits 34 and 35 coincidentto stopping of the lubricant pump 11 will permit the annunicator memberto return to the extended position, thereby indicating to the operatorof the engine that satisfactory operating conditions persist. In theevent that an improper operating condition for the engine occurs, as bythe loss of sufficient lubricant from the lubricant flow cycle to permitthe float 38 to drop and the valve member 40 to move to the seatedposition, the pressure retained in the conduit 34 is released, theannunciator moves to the extended position, and the operator is Warnedof an improper operating condition in the lubricant flow circuit of theengine 10.

While discussed thus far with reference to an apparatus for warning anoperator of an improper lubricant flow circuit condition, it isadditionally contemplated that the apparatus of my invention may be soarranged as to warn an operator of improper coolant flow through theengine. Such a system is shown in FIGURES 57, wherein correspondingportions of the apparatus are identified by the same referencecharacters used in the combination of FIGURES 1-4, with the addition ofprime notation as will become more clear hereinafter. As to thecombination which is particularly adapted for warning of an impropercoolant flow, the internal combustion engine 10 is there shown ingreater detail and in section, in order to illustrate a coolant jacket41 enclosing a cylinder of the engine, for permitting the flow of acoolant liquid such as water in the area immediately surrounding thecylinder. As is well known, the flow of coolant to such a jacket 41 isinduced by an engine driven pump which circulates liquid through theengine and to some heat exchanger such as a radiator.

In order to respond to the pressure developed by the coolant pump, aconduit 42 is provided for establishing operative communication betweencoolant jacket 41 and an expansible chamber 31' within a housing 20. Bymeans of the conduit 42, whatever pressure is applied to coolant flowingin the jacket 41 is transmitted to a displaceable diaphragm membrane28'. As a result, the warning apparatus responds to a decrease incoolant pressure such as results from a rupture in the coolant flowcircuit and to a continuance of high coolant pressure such as resultswhen the engine is stopped but gases from the cylinder have escaped intothe coolant flow circuit.

More particularly, the operation of the combination for the presentinvention as illustrated in FIGURES 5-7 is dependent upon normal riseand fall of coolant pressure Within the jacket 41 and upon the influenceon that pressure of the presence of an improper operating condition.Normally, prior to engine start-up, the pressure applied to the coolantwithin the jacket 41 is substantially atmospheric and is insufiicient toovercome the resilient biasing force applied by the spring 32'.Accordingly, the pivoting flag 21' is positioned in the extendedposition. On start-up of the engine, the pressure applied to the coolantwithin the jacket 41 rises, overcoming the biasing force of the spring32' and raising the pivoting flag 21' to the retracted position.Thereafter, should the coolant flow circuit rupture during operation ofthe engine, the pressurization normally applied to the coolant withinthe jacket 41 will drop rapidly, permitting spring 32' to return thediaphragm member 28' to the reduced chamber volume position and causingthe pivoting flag 21 to drop to the extended position and warn anoperator of the engine. Further, should some engine failure such as aleaking head gasket permit pressure from one of the operating cylindersof the engine to flow over into the coolant jacket, as is typical withsuch an occurrence, the pressure within the jacket 41 will not fall uponstopping of the engine 10 and the pivoting flag 21 will not be returnedto its normal extended position. In either instance, the attention of anoperator will be drawn to the unexpected movement or failure to move ofthe pivoting flag 21, warning the operator of an improper coolant flow.

In the drawings and specification, there has been set forth preferredembodiments of the invention, and although specific tenms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaims.

I claim:

1. In an internal combustion engine having a pump circulating a liquidtherethrough during operation of the engine, the combination therewithof apparatus for Warning of an improper operating condition of theengine and comprising:

a housing,

means for normally establishing operative communication between saidhousing and the pump for normally transmitting to said housing thepressure de veloped by the pump in circulating liquid through theengine.

means in said housing for movement in response to fluctuations inpressure developed by the pump as transmitted to said housing andincluding an actuating rod restrained by said housing to linear movementalong an axis of reciprocation, and

visual signal means supported by said housing in a position for readyobservation by an operator of the engine and including a pivoting flagmounted on said housing for movement about a pivot axis offset from saidaxis of reciprocation, said pivoting flag having a cam surface thereonextending in predetermined spaced relation to said pivot axis andintersecting said axis of reciprocation, said actuating rod beingoperatively coupled to said cam surface for movement of said flagbetween extended and retracted positions indicative of the operatingconditions of the engine in response to linear movement of saidactuating rod,

so that the fluctuations in pressure developed by the pump during normalengine operation causes the pivoting flag to move between the extendedand retracted positions and failure of such movement warns the operatorthat the engine is operating improperly.

2. The combination of claim I particularly adapted for warning anoperator of improper coolant flow through the engine and wherein saidmeans establishing communication between the pump and said housingcomprises a conduit connected at one end to a coolant jacket enclosing acylinder of the engine and connected at the other end to said housingfor transmitting thereto whatever pressure is applied to coolant flowingin the jacket, so that the warning apparatus responds to a decrease incoolant pressure such as results from a rupture in the coolant flowcircuit and to a continuance of high coolant pressure such as resultswhen the engine is stopped but gases from a cylinder have escaped intothe coolant flow circuit.

3. The combination of claim 1 wherein said visual signal means is sooriented that said pivoting flag is biased by gravity toward theextended position and is moved by said actuating rod against gravitytoward the retracted position.

4. The combination of claim 1 particularly adapted for warning anoperator of improper lubricant supply to the engine and wherein saidmeans establishing communication between the pump and said housingcomprises a conduit connected at one end to an outlet from an engine oilpump and at the other end to said housing for transmitting thereto thepressure applied to oil flowing to the engine and further comprisingvalve means interposed in said conduit and operable in response to areduction in the volume of lubricant in a reservoir from which theengine oil pump is drawing lubricant for closing said conduit, so thatthe warning apparatus responds to a loss of lubricant from the reservoirand to a loss of oil pressure such as may result from a rupture in thelubricant flow circuit.

5. The combination of claim 4 wherein said valve means comprises a floatmember normally submerged in and buoyed by lubricant in the enginereservoir, a valve passage interposed in said conduit connecting saidchamber and the oil pump and including a valve seat, and a valve membermovable in said valve passage in response to movement of said floatmember and for engaging said valve seat and sealing against flow therebyupon movement of said float member to a position indicative of excessiveloss of lubricant from the reservoir.

References Cited UNITED STATES PATENTS 1,296,148 3/1919 Witham 116--114XR 1,510,281 9/1924 Jencick.

1,567,821 12/1925 Sweetland.

1,842,518 1/1932 Farmer 116-127 1,874,263 8/1932 Fahrney 12341.l5 XR1,926,180 9/1933 Rutherford.

2,137,495 11/1938 Kershaw 1l6--65 2,477,725 8/ 1949 Dall 116-1143,292,427 12/ 1966 Mattson 73l 18 LOUIS J. CAPOZI, Primary Examiner U.S.c1. XR.

